Field of the Invention
Aspects of the present invention relate to an inkjet apparatus in which a sensor unit is mounted on a carriage.
Description of the Related Art
A serial inkjet printing apparatus is discussed in Japanese Patent Application Laid-Open No. 2002-361858 and Japanese Patent Application Laid-Open No. 2007-62222. A serial printing apparatus forms an image by repeating an operation for discharging ink from a head while moving a carriage and an operation for step-feeding a sheet.
In such a serial printing apparatus, when the carriage moves, turbulence occurs around the print head and between the print head and the sheet possibly disturbing the ink landing position. Japanese Patent Application Laid-Open No. 2002-361858 discusses a configuration in which a rectifying skirt is provided at a lower portion of a carriage to rectify turbulence to prevent degradation of image quality. On the other hand, Japanese Patent Application Laid-Open No. 2007-62222 discusses a configuration in which a sensor unit is attached to a side of a carriage to optically detect sheet information.
Simply combining Japanese Patent Application Laid-Open No. 2002-361858 and Japanese Patent Application Laid-Open No. 2007-62222 provides an embodiment in which a sensor unit is supported outside a carriage and a rectifying skirt is supported outside the sensor unit. In this case, a level difference or gap occurs at a connecting portion of the carriage and the sensor unit. Therefore, even if a rectifying skirt is provided, turbulence occurs at such a level difference or gap making it impossible to obtain sufficient rectification effects.
When the inkjet head discharges ink, unintended ink mist occurs. In an embodiment in which a rectifying skirt is provided, much ink mist adheres to the undersurface of the rectifying skirt which therefore is likely to become stained. If the rectifying skirt is stained to a further extent, mist may liquefy possibly dropping to a sheet or platen. In addition, ink mist is likely to adhere to components of the sensor unit, such as a light emitting element and a relight receiving element. This mist stain may cause degradation of the detection accuracy of the sensor.